Toilet seats which combine both an infant and an adult seat are well known in the art and reference is made in this regard to U.S. Pat. Nos. D. 306,899, D. 281,193, D. 305,357, 548,367, 904,053, 1,196,427, 1,236,902, 1,520,301, 1,616,020, 1,636,649, 1,739,001, 1,990,869, 2,047,480, 2,221,991, 2,434,889, 2,461,160, 2,692,992, 3,609,775 and 4,181,988, Australian Patent 110,261 and U.K. Patent No. 1,218,765, all of which disclose various approaches to this product.
For the most part however, commercial acceptance has eluded combination seats due to a number of factors including aesthetics, costs, inconvenience and poor cleanability. Another factor is that after the infant has grown, the purchaser must either live with the additional and no longer needed seat or dispose of the entire unit at considerable cost. Some prior units allow the infant seat to be removed when no longer needed, but visual evidence that the unit was once a combination seat usually remains, the evidence being in the form of gaps, unused recesses, bulk and weight.